我正在尝试构建U-boot。完成make xconfig后，我跑步
make CROSS_COMPILE=aarch64-linux-gnu-
我遇到此错误：
OBJCOPY u-boot.srec
OBJCOPY u-boot.bin
OBJCOPY u-boot.hex
fatal: bad revision 'HEAD'
Building board/amlogic/gxl_p212_v1/acs.bin
fatal: bad revision 'HEAD'
Building board/amlogic/gxl_p212_v1/bl21.bin
CPP user_task.lds
aarch64-linux-gnu-cpp: error: unrecognized command line option ‘-mthumb’
aarch64-linux-gnu-cpp: error: unrecognized command line option ‘-mno-sched-prolog’
make[2]: *** [/media/saleh/NEWVOLUME/UBOOT/openlinux/uboot-2016-08-18-edd7f116ab/build/scp_task/user_task.lds] Error 1
make[1]: *** [bl301.bin] Error 2
make: *** [sub-make] Error 2
有人知道是什么问题吗？